Door closure



March 16, 1965 D. J. BEECHER 3,173,572

DOOR CLOSURE Filed May 28, 1962 INVENTOR. DONALD J BEECHER United StatesPatent 3,173,572 DUOR CLOSURE Donald J. Beecher, Erie, Pa, assignor toAmerican Sterilizer Company, Erie, Pa, a corporation of PennsylvaniaFiled May 28, 1962, Ser. No. 1%,145 ll Qlaims. (til. 220-46) Thisinvention relates to door closures and, more particularly, to fastenersfor door closures.

In closures for sterilizers, autoclaves, and the like which are designedto contain high pressure gases, it is necessary to seal and firmly clampthe door at several places around its periphery by a mechanical clampingmeans. When the ordinary type clamp having radially disposed arms isused, some of the generally radially disposed members will invariablyexert a greater clamping force than others due to mechanicalinaccuracies and manufacturing tolerances of the parts. This results insome of the clamping members exerting a considerable force while othersexert hardly any force. This obviously results in an uneven clamping ofthe door.

It has been discovered that by providing fulcrums in the form of ballsor cylinders for the arms to swing on and by making the part of the armor the part of the door engaged by the arm of ductile material, anexcessive force on any one of the clamping members will cause theparticular fulcrum ball supporting that arm to brinell itself into theductile material.

When the door is clamped thereafter, the inaccuracies of the arms willbe compensated for by the balls and all of the clamping members willexert a uniform clamping force when the door is clamped thereby. Theductile material is thus self-compensating and gives the effect of ahydraulic clamping mechanism wherein all of the clamping members areclamped by a substantially equal force.

By controlling the hardness of the material, the ball can be made tobrinell more or less deeply with a given force. Thus, the closure can bedesigned to adapt itself to a variety of applications.

It is contemplated within the scope of this invention to use a cylinderas a fulcrum member. A cylinder has advantages over a ball as a fulcrumin certain applications; however, in other applications, a cylinder mayint oduce a torsional force on the radiating arm and, in suchapplications, a ball may be used.

It is, accordingly, an object of the present invention to provide animproved door assembly.

Another object of the invention is to provide an improved clampingdevice and closure combination.

A further object of the invention is to provide an improved combinationclosure clamping means and autoclave.

Still a further object of the invention is to provide a door assemblywhich is simple in construction, economical in manufacture, and simpleand efhcient to use.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawing and more particularlypointed out in the appended claims, it being understood that changes maybe made in the form, size, proportions, and minor details ofconstruction without departing from the spirit or sacrificing any of theadvantages of the invention.

In the drawing:

FIG. 1 is an end view of an autoclave showing an improved door andclamping assembly according to the invention in position thereon;

FIG. 2 is an enlarged view of a door and clamping means;

FIG. 3 is a cross sectional view taken on line 3-3 of FIG. 2; and

3,173,572 Patented Mar. 16, 1965 H6. 4 is a partial view of anotherembodiment of the invention.

Now with more specific reference to the drawing, an autoclave St} isshown in the embodiment of FIGS. 1 to 3. The autoclave is of the usualtype supported on downwardly extending legs and having a door 1. Thedoor 1 is made of a round disk or plate like member having a groove onthe inside thereof adjacent to the peripheral edge which receives anO-Shaped door gasket 23. The door could be square, rectangular, or anyother suitable shape within the scope of the invention. Any suitablegasket could be substituted for the member 23. The door will be made upof a sufiiciently heavy material so that it can withstand the necessarypressures which are likely to be exerted on it.

The door clamping mechanism for clamping the door 1 in place is made upprincipally of the six arms 6 which radiate from a central hub 29. Thesix arms are disposed etween spaced posts 17 and under a retainer roll18 and rest on a fulcrum ball 16. The fulcrum balls 16 are made of ahardened material such as hardened steel and they are supported inretainers 15 which form a nest for each ball.

in practice, the material of the arms directly over the balls could bemade of ductile metal such as aluminum or soft iron so that when anexcessive force is exerted on any one of the arms, the ball supportingthat arm will brinell itself into the material of the arm, therebyeffectively lowering the fulcrum and thereby reducing the load on thatarm and distributing the load equally to the other arms. The ball couldalso rest on the door itself if the door is made of a suitable ductilematerial so that the ball would brinell itself into the door.

The door 1 has a central hole therein which receives the central hub 29.The central hub extends through the central opening in the door 1 and isclamped thereto by means of a flange 3 which is integral with thecentral hub 29. The flange 3 has spaced holes which receive ringretainer studs 3. The central hole in the door is counterbored toreceive a sealing ring 2 which forms a seal between the hub and thedoor.

The hub 29 has a cylindrical portion 3% which slidably receives a hubretraction member 5 The hub retraction member 5 is generally cylindricaland has an external peripheral groove 31 which receives the inner endsof the arms 6. Pins 25 extend through holes in the arms as well asthrough the upper flange or" the retraction member 5. Each arm 6 has acounterbore 32 therein which receives a spring '7. The springs 7 urgethe inner ends of the arms 6 to swing around the fulcrums to theposition shown.

The outer part of the retraction member 5 has a first counterbore 33 anda second counterbore 34. The first counterbore 33 is of equal dimensionwith a counterbore 35 in a handwheel 13. A thrust bearing 11 is receivedin the counterbore 35.

The handwheel 13 has an inner flange which is received in the secondcounterbore 34. A retaining ring 14 is disposed in an internal groove inthe flange of the hub retraction member 5. The ring 14 overlies theflange of the handwheel 13 and holds the handwheel in position. Thehandwheel 13 rotates between the retaining ring 14 on one side and thethrust bearing 11 on the other.

The outer end of the hub 29 is threaded as indicated and it threadablyreceives an insert sleeve 12. 'The insert sleeve 12 has a flange 27which acts as a stop for the handwheel 13. When the handwheel 13 isrotated to move the sleeve 12 toward the door 1, the handwheel actsthrough the thrust bearing 11 and forces retraction member 5 toward thedoor. This causes the arms 6 to swing about the fulcrum balls 16.

A cap 26 is attached to the hub 29 by means of a cap screw 25. The capscrew 25 clamps a washer 36 berotation by a pin 28. Handles 19 are fixedto the handwheel 13. The door 1 is swingably attached to the autoclaveby means of a hinge 21'held to the door by cap screws 22. When the dooris closed and the ends of the arms 6 are extended under a rim 37 and thehandwheel 13 is tightened by means of the handles 19, the door 1 will beclamped in sealed relation.

When the door is clamped for the first time, some of the arms 6 maycarry a greater load than others. This will result in non-uniformclamping. When an excessive force is exerted .on the handle 19, theballs 16 supporting those arms which are carrying more than their partof the total load will brinell themselves into the arms or the dooritself, if designed as aforesaid. This will equalize the load. When thedoor is subsequently clamped, the arms will exert equal forces.

In the embodiment of the invention shown in FIG, 4, a cylinder 116 isshown substituted for the ball 16 of FIG. 3. The cylinder 116 issupported between retainers 115 on a door 101 and engages an arm 106. Acylinderv may have certain disadvantages over a ball as a fulcrum; yet,in some instances, it may have advantages.

The surface that the radial arm engages on the end of the autoclave is,in essence, a plane. The surface which 4 arm spaced from said fulcrummeans and adapted to engage a clamping means on a device to be closed.by said 'door, and means to exert a force on the end of each said armremote .from said means tp engage said clamping means whereby said armsexert anon-uniform clamping force on said door, said fulcrummeanscomprising a member made of ductile material and a relatively hardmember engaging'said ductile material, said hard member being adapted toibrinell said ductile material on the one of said arms carrying moreclampingforce than the others whereby the forces on said arms areequalized whereby said means to exert a force on the ends of said arms'is subsequently actuated.

6. Adoor assembly comprising a door member, arm members on one: side ofsaid door member radiating from the center thereof, the outer end ofeach said arm member having means to engage a member on a device to beclosed, a fulcrum at an intermediate position on each said the oppositeend of the radial arm engages is also a plane. 1

If the fulcrum between these two planes consists of another third plane,it can create in the arm a torsional stress between the fulcrum and theend ring as well as between the fulcrum and the plate at the door post.The presence of a sphere as a fulcrum eliminates the possibility of thiscondition between fulcrum and either surface. It is true that therestill can be a torsional stress but it is between the ends of the radialarm and not between the fulcrum and the end.

It might be advantageous to use an ordinary cylinder. as a fulcrum. Thecylindrical fulcrum could also brinell in the ductile material of thearm and/ or door.

arm'member-between the said arm member and said door member, and meansto exert a force on each said arm member to swing it about saidfulcrum,'said fulcrum comprising a member made of ductile material and arelatively 1 hard member adapted to permanently brinell said ductileinaterial'when a force thereon exceeds a predetermined value wherebytheload carried by each said arm member is equalized wherebysa'id'meansto exert a force on said arm members is subsequently actuated.

7. A door assembly comprising a door, a plurality of spaced arm membersattached to one side of said door and radiating outwardly from thecenter thereof, fulcrum means adjacent an end of each said arm member,means on each said arm member spaced from said fulcrum means on eachsaid arm member adaptedto engage a clamping means on a device to beclosed, said arm members, fulcrum means, and 'means-on'said arm membersbeing adapted to exert uneven clamping forces on said device i to beclosed, and means to. exert a force on the end of each The foregoingspecification sets forth the invention in its preferred practical formsbut the structure shown is capable of modification within a range ofequivalents without departing from the invention which is tobeunderstood is broadly novel as is commensurate with the appendedclaims; v

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined asfollowsz' 1. A door assemblycomprising a'door, a hub member supported on one side of said door, atleast three spaced arms, one end of each said armbeing, engaged by said'hub member, each said arm extending radially from said hub member, afulcrum member disposed between each said arm and said door, means oneach'said arm to engage a member on a device to be closed, said hubmember having means to force the ends of said arms engaged thereby tomove said ends relative to said door, and. means engaging each saidfulcrum member holding each said fulcrum member in fixed relation tosaid door for support.- ng said arm in spaced relation to said door,said means :ngaging each said fulcrum member being made of ductilenaterial whereby said means under any one of said arms raving a greaterforce imposed thereon than the; others s permanently distorted by saidfulcrum member engagng it whereby the forces on said armsare equalizedwhen said arm member remote from said means to engage said clampingmeansysaid fulcrum means each comprising a 7 ball madeof relatively hardmaterial and a seat for said balls between said arm members and saiddoor made of relatively soft ductile material, said balls being,permanently brinelled-into said ductile material when the .forcethereon exceeds a predetermined value whereby theforce carried by eachsaid, arm member is equalized whereby ,said means to exert a force onthe ends of said armmem V hers is subsequently actuated.

8. The assembly recited in claim 7 wherein said means to' exert a forceon said arm members comprises a hub aid means to force the ends of saidarms is subsequently member having means engaging said arm vmembers anda threaded member for forcing said hub member toward said door.

j 9. An autoclave comprising a hollow body having an opening at oneendand a rim spaced outwardly from said :body and extending therearound,a door for saidopening,

said door comprising a plate'like member having sealing means, thereonto engage said door, radially extending arms on the outside of saiddoor, the outer ends of said arms underlying said rim, a fulcrum ballbetween an intermediate part ofeach said arm and said door, each saidball being disposed on a member attached to said door, ahub having acylindrical part'and an outer threaded part, a hub retainer slidablyreceived on said cylindrical part, means onsaid retainer receiving anend of each said arm, a handwheel' threadably received on said threadedpart of said hub, and a thrust hearing between said handwheel and saidretainer, said handwheel being rotatable to exerta force on saidretainer by way 5. A door assembly comprising a door, a plurality ofpaced arms attached to one side of said door and radiat- Jg outwardlyfrom the center thereof, fulcrum means djacent, one end of each saidarm, means on eachsaid of said thrust bearing whereby said retainer isforced to ward said door, rocking said arms" about said fulcrum balls.

10. An autoclave comprising a hollow body, a door, said body having anopeningat one end and a rim spaced outwardly from said door and'extending therearound, said door comprising a plate like member havingsealing means thereon to engage said rim, radially extending arms on theoutside of said door, the outer ends of said arms underlying said rim, afulcrum ball between an intermediate part of each said arm and saiddoor, each said ball being disposed on a member attached to said door, ahub attached to said door, said hub having a cylindrical part and anouter threaded part, a hub retainer slidably received on saidcylindrical part, means on said retainer receiving an end of each saidarm, a handwheel threadably received on said threaded part of said hub,and means between said handwheel and said retainer whereby a force isexerted on said retainer when said handwheel is rotated whereby saidarms are rocked around said fulcrum balls.

11. An autoclave comprising a body having a door opening, opening meanson said body spaced from said door opening for receiving the ends ofarms, a door, spaced, radially extending arms on said door having theirouter ends received under said opening means, a hub at the center ofsaid door attached thereto and extending outwardly therefrom, a retainerslidably received on said hub, a peripheral groove 1n said retainerreceiving the inner ends of said arms, pins extending through saidretainer and each said arm, a fulcrum between each said arm and saiddoor, ductile means engaging said fulcrums, and means for urging theinner ends of said arms toward said door whereby said arms rock aroundsaid fulcrums and clamp said door to said autoclave, said fulcrums beingadapted to permanently brinell said ductile means when the force thereonexceeds a predetermined value to equalize the forces on said armswhereby said means for urging the ends of said arms is subsequentlyactuated.

References Cited in the file of this patent UNITED STATES PATENTS

1. A DOOR ASSEMBLY COMPRISING A DOOR, A HUB MEMBER SUPPORTED ON ONE SIDEOF SAID DOOR, AT LEAST THREE SPACED ARMS, ONE END OF EACH SAID ARM BEINGENGAGED BY SAID HUB MEMBER, EACH SAID ARM EXTENDING RADIALLY FROM SAIDHUB MEMBER, A FULCRUM MEMBER DISPOSED BETWEEN EACH SAID ARM AND SAIDDOOR, MEANS ON EACH SAID ARM TO ENGAGE A MEMBER ON A DEVICE TO BECLOSED, SAID HUB MEMBER HAVING MEANS TO FORCE THE ENDS OF SAID ARMSENGAGED THEREBY TO MOVE SAID ENDS RELATIVE TO SAID DOOR, AND MEANSENGAGING EACH SAID FULCRUM MEMBER HOLDING EACH SAID FULCRUM MEMBER INFIXED RELATION TO SAID DOOR FOR SUPPORTING SAID ARM IN SPACED RELATIONTO SAID DOOR, SAID MEANS ENGAGING EACH SAID FULCRUM MEMBER BEING MADE OFDUCTILE MATERIAL WHEREBY SAID MEANS UNDER ANY ONE OF SAID ARMS HAVING AGREATER FORCE IMPOSED THEREON THAN THE OTHERS IS PERMANENTLY DISTORTEDBY SAID FULCRUM MEMBER ENGAGING IT WHEREBY THE FORCES ON SAID ARMS AREEQUALIZED WHEN SAID MEANS TO FORCE THE ENDS OF SAID ARMS IS SUBSEQUENTLYACTUATED.